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Images from the CLIMSO coronagraphs at Pic du midi observatory in the Pyrenees.

Solar astrophysics have been for almost a century one of the main activities at Pic du midi, where Bernard Lyot in the 1930s conceived and tested coronagraphy for the first time.

Since 2007, with this set of four instruments we carry a long term survey of the Sun: two solar refractors and two coronagraphs. All the images from this survey are available to the scientific community and to the public (from this site). These images cover the whole solar disk with a resolution of 1 arc second, at a frame rate of 1 per minute for each channel, weather permitting. The instruments involved are:

  • Coronagraph "C1" ⊘=20 cm, on the H-α line : λ=656.3 nm Δλ=0.25 nm;
  • Coronagraph "C2" ⊘=20 cm, shared between
    • the He I prominence line λ=1.0830 μm, Δλ=0.25 nm - 90% of the time;
    • the Fe XIII corona line, λ=1.0747 μm, Δλ=0.25 nm - 10% of the time;
  • Solar refractor "L1" ⊘=15 cm, H-α, λ=656.3 nm, Δλ=0.05 nm;
  • Solar refractor "L2" ⊘= 9 cm, Ca II, λ=393.4 nm, Δλ=0.25 nm.

A fifth instrument tracks the Sun using diffractive optics: a coper Fresnel array ⊘=6.2 cm, more than 10^4 subapertures. The images it provides are used for a precise guiding of the other instruments, specially the coronagraphs that need to be centered.

The calibrated images and the films made from them are uploaded on this data base. The images are in FITS format and compressed (*.fts.bz2). For the solar disk images made with L1 and L2, the calibration for each pixel provides a measure in watts m^-2 sr^-1 in the corresponding spectral band. The prominences and corona images by C1 and C2 are not calibrated yet but normalized. All the images are oriented with the North Solar pole up.